1. Field of the Invention
The present invention relates to information processing in a plurality of intranets connected to each other via a network and, in particular, to a system, an apparatus, a method, a computer program, and a recording medium for synchronizing the updating of shared information including a document in the information processing.
2. Description of the Related Art
Information is typically shared among intranets connected to each other via a network, such as the Internet. The shared information is, in general, maintained and managed to the same state (synchronized) by transferring files in the file transfer protocol (FTP). When a file is transferred via a network, the file must pass through a variety of security steps arranged in each intranet. If the networks are different in security policy, sharing information becomes technically and procedurally difficult.
Concerning such sharing information among intranets, when information is shared within the Internet or among a plurality of intranets, a single information management server collects and generally manages information. The information is then opened on that server or a public server for disclosing information to users in a different system. Such a technique is disclosed in Japanese Unexamined Patent Application Publication Nos. 2000-311204 and 2002-373225.
Updated information is transferred in accordance with updating of each database among intranets (Japanese Unexamined Patent Application Publication No. 2000-148611). Updating of information is performed via electronic mails (Japanese Unexamined Patent Application Publication Nos. 2000-285074, 2003-150438, 11-150532, 2000-207305, and 2003-16019). By mutually exchanging information via electronic mails, information is shared and a transmitted schedule is then displayed on a schedule display (Japanese Unexamined Patent Application Publication No. 2002-49567).
When information is managed separately by a plurality of intranets, the shared information can lose consistency. For example, the shared information can be individually updated by each intranet, or updated information cannot be reflected in another intranet. Such an in convenience becomes pronounced when information is shared among intranets of networks different in security policy. When information shared by intranets is updated in response to an update request, an acknowledgement of updating of information is difficult without notification. Information shared by a plurality of intranets that limit access from the outside must be maintained to the same state. Intranet to intranet communications are required in such a case, but it is difficult to clear security restrictions (firewall proxy). In particular, if restrictions different in security policy are applied, it takes time to share information passing through the security restrictions.
Information shared by intranets can be accessed by another intranet to learn the update status of the information, but security restrictions makes it difficult for the other intranet to examine the update status.
The more the number of intranets sharing information, the longer time is required for each intranet to make an access request and to receive an access result. Communications take more time, and replies are delayed. Management of transmission and reception and internal process become complex.
There are no mentions about a solution to these problems in Japanese Unexamined Patent Application Publication Nos. 2000-311204, 2002-373225, 2000-148611, 2000-285074, 2003-150438, 11-150532, 2000-207305, 2003-16019, and 2002-49567.